1. Field of the Invention
This invention relates to a battery box wherein a battery is resiliently contacted with a leaf spring terminal secured to a battery accommodating case.
2. Description of the Prior Art
Battery boxes are already known wherein a battery is resiliently contacted with a leaf spring terminal secured to a battery accommodating case. An example of a conventional battery box of the type mentioned is shown in a partial sectional view of FIG. 3. Referring to FIG. 3, a cavity 2 for removably receiving a battery is formed in a battery accommodating case 1 which is, in one embodiment (for example), made of a synthetic resin material. A leaf spring terminal 3 is secured to the battery accommodating case 1 by having a base portion 3a embedded in one of inner walls of the battery accommodating case 1 at one end of the cavity 2. The leaf spring terminal 3 further has a contact portion 3b for contact with a battery (not shown) accommodated in the cavity 2. The contact portion 3b of the leaf spring terminal 3 is connected to the base portion 3a by way of a folded portion 3c such that the contact portion 3b extends in an opposing relationship to the base portion 3a. Suitable resiliency is provided to the contact portion 3b by a fulcrum formed by the folded portion 3c.
When a battery 10 is received in position into
cavity 2 as shown in FIG. 4, the contact portion 3b of the leaf spring terminal 3 is resiliently contacted with an electrode 11 of the battery 10. The resilient force provided by the folded portion 3c of the leaf spring terminal 3 establishes electric connection between the leaf spring terminal 3 and the electrode 11 of the battery 10.
However, with such a battery box, if one loads or unloads a battery repeatedly or otherwise vibrates the battery accommodating case, then stress is concentrated upon the folded portion 3c of the leaf spring terminal 3. This concentration may cause a settling of the contact portion 3b which may deteriorate the resiliency of that member. Consequently, the contact pressure of the leaf spring terminal 3 upon the electrode 11 of the battery 10 may be lessened, thereby causing incomplete contact between the leaf spring terminal 3 and the battery.
Japanese Utility Model Publication No. 62-37330, as shown in FIG. 5, discloses another battery box. Referring to FIG. 5, the battery box is substantially similar to the conventional battery box shown in FIG. 3, but differs in that a tapered recess 1a is provided in the inner wall of battery accommodating case 1 opposite the intermediate portion 3d of the leaf spring terminal 3 between the base portion 3a and the folded portion 3c. Tapered recess 1a provides resiliency to the intermediate portion 3d, thereby lessening stress concentration upon the folded portion 3c. Consequently, the leaf spring terminal 3 in FIG. 5 suffers less from settling than that of the battery box shown in FIG. 3.
However, even with the battery box shown in FIG. 5, continuous vibrations or strong shocks may cause settling at the contact portion 3b or at the intermediate portion 3d. Hence, external forces may still cause incomplete contact between the leaf spring terminal 3 and the battery.